Genesis 1:31 And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day.
See the Typology of Day 6 in Telescopic Views.
Exodus 16:5 And it shall come to pass, that on the sixth day they shall prepare that which they bring in; and it shall be twice as much as they gather daily.
Exodus 16:22 And it came to pass, that on the sixth day they gathered twice as much bread, two omers for one man: and all the rulers of the congregation came and told Moses.
Exodus 16:29 See, for that the LORD hath given you the sabbath, therefore he giveth you on the sixth day the bread of two days; abide ye every man in his place, let no man go out of his place on the seventh day.
Numbers 7:42 On the sixth day Eliasaph the son of Deuel, prince of the children of Gad, offered:
Numbers 29:29 And on the sixth day eight bullocks, two rams, and fourteen lambs of the first year without blemish:
The sixth day is also called "The Day of the Preparation" that is the day the Jewish people prepare for the Shabbat.
Mark 15:42 And now when the even was come, because it was the preparation, that is, the day before the sabbath,
Luke 23:54 And that day was the preparation, and the sabbath drew on.
Thus, the sixth day is the day before the Sabbath.
The Jews number the days by the number of days after or before the sabbath which is the highlight of the week.
Thus, the first day means the first day after the Sabbath. And so on till the sixth day, the sixth day after the Sabbath.
There is no day numbered in the weekly calendar s the seventh day because that would mean the seventh day after the Sabbath, which itself is the Sabbath.
In our own family observance of the Sabbath, we think of Thursday and Friday as days to anticipate the coming Sabbath, the days to buy or cook something special, and keep it to enhance the Sabbath.
Then the days from Sunday to Wednesday are days to enjoy the afterglow of a Sabbath we delighted in. (Isaiah 58:13)
Isaiah 58:13 If thou turn away thy foot from the sabbath, from doing thy pleasure on my holy day; and call the sabbath a delight, the holy of the LORD, honourable; and shalt honour him, not doing thine own ways, nor finding thine own pleasure, nor speaking thine own words:
14 Then shalt thou delight thyself in the LORD; and I will cause thee to ride upon the high places of the earth, and feed thee with the heritage of Jacob thy father: for the mouth of the LORD hath spoken it.
Delighting oneself in the Lord is defined as making the Sabbath a delight.
That is what we have done in our family since 1994, and God has honored us with weekly blessing, from Sabbath to Sabbath.
There is one more very important and most interesting point about the sixth day.
Matthew 17:1 And after six days Jesus taketh Peter, James, and John his brother, and bringeth them up into an high mountain apart,
Mark 9:2 And after six days Jesus taketh with him Peter, and James, and John, and leadeth them up into an high mountain apart by themselves: and he was transfigured before them.
The Sabbath is a type of the Millennium, which is inaugurated after the sixth prophetic day, the day which speaks of the end times, the times in which we now live.
Our own participation in the day of the Transfiguration of Jesus is the day of the Rapture, when Jesus will appear before us in all His glory, and the dead saints, like Moses, will be raised to immortality, and the living saints, like Elijah will be caught up without passing through death. And we shall all be changed.
Rejoice, for we are in the sixth day, and the seventh day of glory is at hand.